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package com.aternity.geolocations.draw;

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.AffineTransform;

import javax.swing.JComponent;
import javax.swing.JFrame;

public class AffineTransformTest {

    private static TransformingCanvas canvas;

    public static void main(String[] args) {
        JFrame frame = new JFrame();
        canvas = new TransformingCanvas();
        TranslateHandler translater = new TranslateHandler();
        canvas.addMouseListener(translater);
        canvas.addMouseMotionListener(translater);
        canvas.addMouseWheelListener(new ScaleHandler());
        frame.setLayout(new BorderLayout());
        frame.getContentPane().add(canvas, BorderLayout.CENTER);
        frame.setSize(500, 500);
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.setVisible(true);
    }

    private static class TransformingCanvas extends JComponent {

        private double translateX;
        private double translateY;
        private double scale;

        TransformingCanvas() {
            translateX = 0;
            translateY = 0;
            scale = 1;
            setOpaque(true);
            setDoubleBuffered(true);
        }

        @Override
        public void paint(Graphics g) {

            AffineTransform tx = new AffineTransform();
            tx.translate(translateX, translateY);
            tx.scale(scale, scale);
            Graphics2D ourGraphics = (Graphics2D) g;
            ourGraphics.setColor(Color.WHITE);
            ourGraphics.fillRect(0, 0, getWidth(), getHeight());
            ourGraphics.setTransform(tx);
            ourGraphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                    RenderingHints.VALUE_ANTIALIAS_ON);
            ourGraphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
                    RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
            ourGraphics.setColor(Color.BLACK);
            ourGraphics.drawRect(50, 50, 50, 50);
            ourGraphics.fillOval(100, 100, 100, 100);
            ourGraphics.drawString("Test Affine Transform", 50, 30);
            // super.paint(g);
        }
    }

    private static class TranslateHandler implements MouseListener,
            MouseMotionListener {

        private int lastOffsetX;
        private int lastOffsetY;

        public void mousePressed(MouseEvent e) {
            // capture starting point
            lastOffsetX = e.getX();
            lastOffsetY = e.getY();
        }

        public void mouseDragged(MouseEvent e) {

			// new x and y are defined by current mouse location subtracted
            // by previously processed mouse location
            int newX = e.getX() - lastOffsetX;
            int newY = e.getY() - lastOffsetY;

            // increment last offset to last processed by drag event.
            lastOffsetX += newX;
            lastOffsetY += newY;

            // update the canvas locations
            canvas.translateX += newX;
            canvas.translateY += newY;

            // schedule a repaint.
            canvas.repaint();
        }

        public void mouseClicked(MouseEvent e) {
        }

        public void mouseEntered(MouseEvent e) {
        }

        public void mouseExited(MouseEvent e) {
        }

        public void mouseMoved(MouseEvent e) {
        }

        public void mouseReleased(MouseEvent e) {
        }
    }

    private static class ScaleHandler implements MouseWheelListener {

        public void mouseWheelMoved(MouseWheelEvent e) {
            if (e.getScrollType() == MouseWheelEvent.WHEEL_UNIT_SCROLL) {

				// make it a reasonable amount of zoom
                // .1 gives a nice slow transition
                canvas.scale += (.1 * e.getWheelRotation());
				// don't cross negative threshold.
                // also, setting scale to 0 has bad effects
                canvas.scale = Math.max(0.00001, canvas.scale);
                canvas.repaint();
            }
        }
    }

}
